Instinct
by Lizbug
Summary: Sometimes the end is just the beginning. Dean would do anything to protect Sam. It was instinct. Sam is 11, Dean is 15, pre-series AU. Rating T to be safe for language (John's a Marine, I'm fairly sure his boys would swear) and a bit of violence. Disclaimer: Don't own 'em, obv. Word Count. approx. 4000. Please review! 1st in "The Siren Call" series.
1. Prologue

Prologue

Sam knew it was stupid before he did it. He knew it was stupid but he was mad and his dad had been riding him all day, hell, all week. He knew it was stupid and he did it anyway, which was why he shouldn't be surprised that he was lying hunched up against the impala's wheel hub staring into the gaping maw of a fucking huge dog and all he could think was _that was stupid_, well that and _Dad's going to kill me_ and _holy shit, look at those teeth_. But mostly he was thinking that getting out of the car was the worst idea he'd ever had in his life and then he was wondering why he wasn't dead yet because the dog had lunged forward and Sam hadn't moved but suddenly there was something in between them. There was something in between them and Sam was relieved because, hey, not dead and then he realised that the something was someone and that the someone was Dean and the relief turned into _Oh my God I'm so sorry_ and _pleasenopleasenoplease_ because Dean was on the ground and his arm was in the dog's mouth so his gun was flailing uselessly and then it wasn't his arm in the dog's mouth but his neck and his brother was going to die and it was all Sam's fault for getting out of the fucking car.


	2. Chapter 1

Chapter 1

At first John couldn't figure out why the growling was coming from behind them, not right behind them 'cause that would have been pretty easy to figure out, but far enough back that they couldn't see what it was coming from and then John didn't need to figure it out because Dean was running, full out back the way they'd come and if Dean was running that meant he'd figured it out and John should be running too.

So John ran after Dean still wondering what had made his 15 year old son run without orders, without checking what his dad wanted him to do, because Dean was a good hunter but he was also a good soldier and he usually checked.

While John was wondering this Dean had pulled far ahead and John thought maybe he was getting old but then again maybe not because _God damn that boy can run_ and now his boy was out of sight and the snarling and growling was getting louder and then it cut off with a thump and a scrape of gravel.

The snarls began again and John was listening for the gunshot, but it never came. John ran faster. Thirty seconds felt like hours as he ran, lungs burning and legs screaming.

He ran because he couldn't see his boy, he ran because the copper scent of blood was beginning to overpower the red pine of the Pennsylvanian forest and he ran because he'd finally figured it out.

As he rounded the corner John brought his weapon to bear, his to-do list circling like a mantra in his head; _take out the threat, find my sons, take out the threat, find my sons_. Then he cleared the last of the trees obscuring his vision and all his thoughts screeched to a halt, he'd found his sons.

Sam was crouched next to the wheel of the impala a low, keening wail coming from his open mouth, his eyes fixed on the massive dog that pinned his brother to the ground.

In the full moon light John could pick out the splatters of blood on its cream coat from where it had torn into Dean. _That's not a werewolf,_ he thought fleetingly before he sighted down the barrel of his 9mm, _who the fuck cares._

He fired and saw the impact through the ribcage of the animal and then he kept firing because silver bullets or not that thing was big and it was chowing down on his son and maybe it was supernatural or maybe it was just a vicious dog but John didn't care because his boy, his Dean, was lying there bleeding and that thing was going down.

The dog kind of shuddered and its fur began to melt away leaving a short, fat, balding man in his forties lying on top of his son, naked.

John ran forward and shoved the man off of Dean, all the while begging his son to respond. Dean's eyes fluttered and his left hand flapped a little.

"Sam! Sam! Get the first aid kit out of the impala." John dropped to his knees beside Dean; he placed his hand over the macerated flesh and pressed hard.

His marine training overcame his panicking parent brain and he became eerily calm as he began to evaluate the casualty. Not Dean, not my son, but the casualty. There was blood everywhere but it wasn't spurting so at least John was fairly sure that the arteries were intact. Of course, there was still too much damage for him to even begin dealing with it on his own which meant he needed medics and there was no way he could move Dean without killing him so he needed them to come to him.

His eyes flicked up to the corpse of the skin-walker he'd rolled off his son. "Sam! Move your ass!"

Sam appeared almost instantaneously with their med kit and began pulling out gauze like it was going out of style. "He's got another bite wound on his right arm." Sam whispered in a choked voice, his eyes on his brother's pale face. "Okay Sam, you bandage that one while I do his neck. Make sure it's real tight Sam okay?" His eleven year old nodded his head shakily and got to work wrapping a sloppy but tight bandage around Dean's forearm while John shoved gauze onto the wound just above Dean's shoulder without releasing the pressure. _First clot's the best clot_ he thought as he resisted the urge to lift his hand and check whether the bleeding had slowed. He was going to have to move soon anyway but at least he could give the clot a little more time to form before he risked it getting dislodged.

Sam pulled away from Dean's arm, his hands liberally coated in his brother's blood, and John called him over. Looking at his youngest he decided that Sam didn't really have the muscle mass to maintain the kind of pressure he needed, bodyweight would have to do. "Good job Sam, I need you to do something else for me now okay? I need you to get real close and when I move my hands I need you to put your knee right where that bandage is and then put all your weight on it okay? Don't worry about hurting your brother." Dean had passed out almost as soon as Sam had come over, almost as if that's what he was waiting for which, knowing Dean, it might have been.

John stood up, letting Sam take his place, and ran to the trunk of the impala. He opened it, stowing his and Dean's guns in their hidden weapons cache, and dialled 911. He talked to the dispatcher as he went back to the body, lifting it in a fireman's carry as he deposited that into the trunk as well. He took out a road flare before he closed the impala and returned to Sam, handing him the flare and telling him to wait for the ambulance.

Once he'd done what needed to be done his emotions began to seep through again. He knelt next to the stricken form of his son and for the first time in a long time he prayed.

Sam tried not to think as he stood by the impala gripping the unlit flare in his hand. He didn't want to think about Dean dying and he didn't want to think about what would happen if he survived. He wasn't exactly sure what it was that had bitten Dean but he knew that his dad had killed it with silver and that meant maybe it was kind of werewolf-ish and a bite from a werewolf makes a new werewolf, so Sam tried not to think.

When he saw the flashing lights coming up the road he lit the flare and began waving it back and forth, lowering it to his side only when the ambulance screeched to a halt and two paramedics tumbled out. They ran to the rear of the ambulance and pulled out a big yellow board and some bags, racing over to his brother still lying pale and still on the ground.

Sam was so intent on the medics that he barely noticed the state police who pulled up just after them until one of them grabbed him by the shoulder and gently guided him away. "No Dean, I wanna go with Dean!"

The lead medic took one look at the blood pooled around his brother and called out "Scoop and run!" his voice sharp and piercing in the still night air. The staties left Sam and ran to help as the paramedics rolled Dean onto the board. They hefted it between them and quick-marched to the ambulance, stumbling slightly on the rough ground beside the road.

Sam could see one of the medics attaching things to Dean as the other closed the rear doors and ran to the driver's side. Just like that Dean was gone. Sam's dad stumbled to his feet and shakily made his way over to the impala talking quietly to one of the troopers as the other swept his flashlight beam into the trees. Sam heard the words "Riverside hospital" and pelted towards the car leaving the police to look for a dog that wasn't there anymore.


	3. Chapter 2

Chapter 2

Dean's first muzzy awareness was of sound: squeaking wheels and pounding feet, shouts in anxious voices, and the throbbing, thumping, hammering of his heart.

_What happened?_ He wondered.

He struggled towards consciousness, the pain in his neck and forearm helping him focus even as it made him want to sink back down into the dark. _Sammy_ he thought and forced himself up again.

The voices began to form words, "Dean Hughes. Fifteen year old male with a dog bite to left side of the neck and right forearm, unconscious at scene, BP 86/40, pulse tachy at 120. He had a litre of saline wide bore en route; cannula is in the left ACF. We had to scoop and run."

Hands grabbed him and he felt the cool presence of a blade against his skin, he tried to move but his limbs were sluggish, his mind foggy, "Type and cross-match! And grab some O-neg!" His left arm finally decided to cooperate, scrabbling weakly at the scissors that were slicing through his favourite shirt, "He's waking up! Dean, Dean Can you hear me?"

Dean tried to nod, tried to speak, "Open your eyes Dean." His eyelids fluttered, light suddenly spearing his eyes, "Nngmmnnng" he complained.

Soft hands brushed his hair back from his forehead and a face shimmered into view. Bright blue eyes caught his and he blinked, focussing on the features above him, _pretty, nice_. "Dean? My name's Beth I'm a doctor at Riverside Hospital. We're taking care of you okay? But I need you to try and stay still for me." He blinked again in agreement and then concentrated on forming words, "Where's S'mmy?" he asked, his voice sounding weak and raspy, "Smee? Who's Smee?" Another voice replied so he didn't have to, "I think it's the brother, Dean jumped in front of his little brother, saved him from the dog" Dean's mind categorized the voice as _Cop_. The cop began speaking to him as the doctor's face disappeared, he could still feel her hands on him though, gently working at his shoulder. A wave of warmth spread through him, _painkillers…nice_. "Your brother's fine Dean, he and your Dad are on their way here. You saved Sammy from the dog." _Dog?_ Dean thought, and then _werewolf, shit b_efore the world slid away on a morphine induced cloud.

When Dean woke again his head was clearer, his movements easier. He could feel the soft itch of bandages against his skin, the tight pull of stitches in his neck and arm. A warm weight was pressed against his legs. He shifted, seeking more of that comforting warmth.

The strong smell of disinfectant reached his nose and he huffed out from the sting. "Dean?" _Dad_, Dean opened his eyes to see his dad's weary face looming over him. The weight on his legs was lifted and Sam's face joined his dad's. Dean felt his lips lift in a smile, "Sammy" he breathed, "Hey Dee, how're you feeling?" Dean smiled again, widening it to include his dad, and blinked sleepily. His dad's hand squeezed his good shoulder, "Sam, why don't you go let the nurse know that your brother's awake."

The expression on his dad's face immediately focussed Dean's sleep-fogged brain. _Oh God I'm gonna be a werewolf,_ terrified green eyes met brown. "Find someone else to do it Dad okay? I don't want it to be you." Confusion flittered across John's face briefly before realisation dawned. Dean saw the denial before it reached his dad's mouth, "I'm gonna be a fucking werewolf Dad!" he blurted out as John shook his head. "It wasn't a werewolf son," hope soared in Dean's chest before his father continued, "It…it was a skin-walker."

And just like that the hope was snuffed out.

"We're going to figure this out son okay? As soon as you're better we'll go to Bobby's and figure this out."

Dean didn't say anything, Uncle Bobby was a friend, he was _family_, he would kill Dean and then he would make sure that Dad and Sammy were okay. Dean nodded, Bobby was a good choice.


	4. Chapter 3

Chapter 3

Dean slept through most of the journey to Bobby's, stretched out on the back seat of the impala swathed in blankets. Sam watched him, twisted around in his seat; he didn't take his eyes off of his brother.

Dean had been released from the hospital pretty soon after waking up, the staff were surprised at how well he had healed Sam could tell from the way they talked. Sam wished that Dean had taken longer, he was pretty sure that skin-walkers healed fast. Dean wasn't his brother anymore, but he still felt like his brother; he smiled like his brother and talked like his brother. Sam watched him sleep and decided that he slept like his brother too, snuggled up into the blankets with his face all smooshed from the leather seats.

Sam glanced at his dad, wondering if Dad still felt like Dean was his son. He hoped so. Sam didn't want his dad to kill Dean. Sam stilled, his brain spinning furiously then, suddenly, it settled with one clear and overwhelming truth, _Uncle Bobby always kept his promises_.

Sam sprang from the impala as soon as they pulled up at Bobby's place, racing up to the porch as fast as eleven year old legs could carry him. He grabbed hold of Bobby's shirt, twining his hands in the flannel, nearly incoherent with worry "Promise me! Promise me you won't let Dad kill Dean!"

It took ten minutes for Bobby to disentangle the youngest Winchester's hands from his shirt all the while muttering, "It's alright, I won't, no one's gonna hurt Dean I promise" until, finally the kid calmed down. Glaring at John, who was ushering a groggy and doped up Dean from the car, he snarled, "What the hell did you do to get that kid so worked up?" then growled at John's bewildered expression. "Idjit."

Bobby had started going through the lore as soon as John had called from the hospital five days ago. There was no way in hell that Bobby was letting Dean bite a silver bullet, after all he thought, as he was always telling the boys,_family doesn't end with blood_. He'd gone through everything with a fine tooth comb and had everything laid out as he sat the Winchester's down at his kitchen table in a domestic scene that he thought Karen would have been proud of, if she could ignore the muddy boots and the clutter.

Dean was looking a little peaked as Bobby busied himself making coffee, laced with holy water of course, and sandwiches. He raised an eyebrow at Dean with a little shake of a mug and was rewarded with a wrinkled nose followed by a grin the size of Texas when he plonked two sodas down in front of the brothers instead. Dean had been drinking coffee for a while but Bobby figured it was more to show his dad how grown up he was than because he'd developed a taste for it. Give him time and he'd be guzzling coffee like the rest of them but for now he much preferred a sugar hit over caffeine.

Bobby wondered how many of the hidden stashes of peanut m&amp;ms were still intact around the house and made a mental note to buy some more, it was an easy way of keeping Dean occupied and he'd been doing it for years. Besides it was worth it to see Dean's face light up with genuine delight rather than in the cocky mask that so often graced his features.

Bobby shook himself out of his reverie and brought his mind to the task in hand. Bobby didn't have much family left and he was going to do everything in his power to keep this branch of it whole.


	5. Chapter 4

Chapter 4

"So there's no way to reverse it?" John made Bobby repeat himself for the third time just in case the first two had been the mistakes he was hoping they were. _Deal with it and move on marine_, he told himself and raised his eyes to meet Bobby's. 

Bobby sighed in understanding, "No and he won't be able to just not change, it'll drive him nuts, but there's nothing in the lore that says he's dangerous to people." Bobby could feel the protest emanating from Dean and stopped it with a finger jab before it started, "It's a _choice_ Dean! Do you want to hurt people?" Dean shook his head mutely, "Then you won't. End of discussion."

"Now the important thing is figuring out how to keep this off the other hunters' radar. Some of them'll understand but there's a few who'll shoot ya regardless." The matter of fact statement both reassured and alarmed the Winchesters.

Dean was still trying to process that no one was going to kill him and John was struggling to contain his relief, only Sam was taking the situation in stride; Dean was safe and that was all that mattered to him. "How does he control it?" He piped up from his perch on the arm of the couch stopping the older hunters in their tracks. "You mean you haven't…done it yet?" Bobby asked the unspoken idjits present in his tone. Dean shook his head a look of trepidation on his face, "Well get on with it idjit, the urge must be driven year near barmy!"

Dean stood up hesitantly only to have Bobby stop him, "Wait, wait, take your clothes off first and rap this around yourself." He said, handing Dean a blanket as John went to close the curtains. No one was around to notice but he'd already decided there was no such thing as too careful.

Dean stood in the centre of Bobby's living room, naked apart from a scratchy blanket that had been draped over the couch. Three pairs of eyes watched him intently and he wasn't sure if it was them or the urge to change that was causing the itch between his shoulder blades.

He hummed soothingly to himself while he tried to figure out how to do this, "Dean," his dad groused, "stop humming Metallica and get on with it. Think dog or something." He shot his dad a look before replying, "Somehow I don't think it's as easy as just thinking…oh."

A tingling started in Dean's extremities, travelling up his limbs before settling just under his sternum. _This feels weird_, he said, except he didn't say it he just felt his ears twitch. _I don't normally feel my ears twitch_. He looked at Sammy who had his hands over his mouth and the strangest look on his face and then turned to Bobby and Dad, his tail swishing against the blanket. _Oh my God I have a tail!_

"What breed did you say bit him?" Bobby asked, his lip twitching in a suppressed grin, "Mastiff," Dad replied, "big fucker. Guess the breed doesn't get passed on with the bite." Dean cocked his head, he wasn't sure what reaction he was expecting but amusement hadn't made the shortlist. His dad scrubbed a hand over his face, "You're…you're really cute Dean."

Bobby was trying to hold in a laugh as he examined the sight in front of him. Sitting in a puddle of red and grey striped blanket was just about the most adorable german shepherd puppy he'd ever seen. Large brown eyes gazed over a black muzzle surrounded by fluffy red-brown and black fur, "Guess not. Maybe it's a personality thing. Can't be more'n five months old. I wonder if they all start as puppies"

The puppy cocked his head and one of his ears flopped over causing a snort of laughter to break free. "Oh God I need a camera" Bobby chortled as he fled the room.


	6. Epilogue

Epilogue

Dean streaked through Singer Salvage, racing the sound of the impala as it sauntered up the lane. His tongue lolled as he raced the car, bounding over the vehicles that littered the yard.

It had taken Dean about a month to go from five month old puppy to full grown, confirming Bobby's theory that all skin-walkers start as puppies.

He had taken some time to get used to his "dogginess", as Sammy called it, but now could both act like a dog in dog-form and didn't get completely confused by all his extra sharp senses when he was human.

Dean was comfortable in his skin, both of them, and thought that maybe he quite liked being a dog sometimes; like when Sam and Dad were arguing and he could get lost in all the smells in Bobby's house.

He definitely found the hidden m&amp;ms quicker now, although he couldn't open the packets so he just hid them again and went back when he had opposable thumbs.

Sam had wanted a dog since he was about five and had done lots of research on german shepherds and what made them happy. He had roped Bobby into building an obstacle course which both Dad and Dean had ridiculed until Sam said that Dean could help with hunts as a dog too.

Dean was kinda glad he'd said that 'cause now he had an excuse to do it a lot. That thing was a blast, he'd even added to it. The long fur was a bit of a pain because even after he'd changed back it was still itchy if something had gotten into it which meant that someone needed to brush it for him. Sammy did that and Dean kinda loved it, so much so that he changed at least once a day even if he didn't really need to anymore.

He liked sitting or lying next to Sam while his little brother worked hands and brush through his fur, snuggling with Sam was pretty cool now that he could be all doggy about it. Plus Sam got so much attention from chicks now, well okay Dean got the attention but he figured it had to rub off a little bit and his brother was such a geek he needed all the help he could get.

The collar and lead were a bit of a pain when they went into Sioux Falls but the cooing and petting were so worth it. His coat, so Sammy told him, was long-haired, black and red, with a medium blanket and mask and, in Dean's opinion, it definitely made him the handsomest german shepherd around. _After all how he could he not be?_ Dean thought as he bounced up to his dad, tail wagging frantically at the familiar scents of leather, salt, smoke and gunpowder.

"Hey Dee," Dad crouched down and scratched behind Dean's ears, "Do you think you've got a handle on this thing yet? I've caught wind of a wendigo up in Silver Creek, Minnesota." _Finally_, Dean gave a single bark and trotted into the house, beating his tail against his dad's leg, _I'm going hunting!_


	7. Sequel

The sequel to Instinct can be found here:

s/11184597/1/Silver-Creek

**Silver Creek, Minnesota, 1994**

It is Dean's first hunt since the skinwalker attack. Something has its hunting grounds in Silver Creek, Minnesota and he and his dad are there to stop it. How will his new circumstance affect Dean? Crossover with Stargate SG-1.

Sometimes you meet your destiny, on the road you took to avoid it


End file.
